Support for signing and ratifying the United Nations Treaty on the Prohibition of Nuclear Weapons has already been endorsed by 78 per cent of members of the parliamentary Labor Party. They include national president Wayne Swan, deputy leader Tanya Plibersek, shadow treasurer Chris Bowen, Tony Burke, Mark Dreyfus, Mike Kelly, Joel Fitzgibbon, Linda Burney, Catherine King, Brendan O’Connor, Anthony Albanese and Patrick Dodson. More than 20 leading trade unions have joined the ACTU in this cause.

Despite existing party policy supporting the negotiation of the treaty, not all in the ALP leadership are yet strong supporters. Shadow foreign minister Penny Wong told the Australian Institute of International Affairs recently that ratifying the treaty would risk impacting on Australia’s alliance with the United States. Senator Wong has reconfirmed that Labor’s support for the alliance is unshakable.

In 1996, a Coalition government led Australian support for the Land Mines Treaty, despite the fact that this did not – at the time – please the US. No doubt, Australia signing the nuclear ban treaty would require diplomatic engagement with the US, and reassurances, but we would not be alone. Most major non-NATO allies of the US – with strategic working relations – support the treaty. New Zealand has already signed and ratified the treaty, with the unanimous support of its parliament and without controversy.

Wong’s speeech said the “International Court of Justice is clear in its view that there is no circumstance in which the use of a nuclear weapon would be consistent with International Humanitarian Law”. Respectfully, this is not true. The court, in 1996, expressly declined to so rule. This “gap” in international humanitarian law was a key driver of the push by a Nobel Peace Prize-winning organisation, the International Campaign to Abolish Nuclear Weapons (ICAN), the International Committee of the Red Cross (ICRC), and the International Red Cross and Red Crescent Movement for a treaty to outlaw the use of nuclear armaments as weapons of war in all circumstances and for all time.

Wong suggested support for the treaty, which requires safeguard agreements with the International Atomic Energy Agency, would undermine the existing safeguard provisions of the Nuclear Non-Proliferation Treaty. Not so, according to the the ICRC.

Australia and the US will have sensitive and confidential discussions over Pine Gap, but this can be resolved. The campaign to outlaw nuclear weapons has never been about closing Pine Gap or campaiging against the alliance.

Senator Wong recognised “there is no doubt that the [nuclear] ban treaty and the campaign surrounding it has already had a significant normative impact”. ICAN welcomes this acknowledgement. It is the fundamental purpose of the treaty, just as it was in the treaty banning land mines. The nuclear ban treaty would increase pressure on the nine nuclear weapons states to disarm.

Senator Wong rightly asserts that simply becoming part of the treaty is not enough; Australia and other like-minded powers must use their influence to bring the nuclear weapons states to the negotiating table. However, this is what Article 6 of the Nuclear Non-Proliferation Treaty has required of those states for almost 50 years – and has failed thus far to achieve.

An Ipsos opinion poll a month ago showed that 78.9 per cent of Ausralians – and 83 per cent of Labor voters – support joining the treaty. Only 7.7 per cent were opposed.

Australia should tell the world that nuclear weapons must never be used in our name. Our stand would be welcomed by the 122 nations already supporting the treaty, including our largest neighbour, Indonesia, and almost all our other Pacific and south-east Asian neighours.

The moral and legal case against nuclear weapons are surely unanswerable.

Robert Tickner is a former Labor Minister for Aboriginal and Torres Islander Affairs. He wasCEO of Australian Red Cross, 2005-15, and is now an ICAN ambassador.